eCommons

 

Using Movement Ecology To Understand Flight Behavior In Soaring Birds

Other Titles

Abstract

Understanding the process by which animals make decisions based on cues in their environment is a central challenge in behavioral ecology. We focus here on the process by which soaring migrant birds use landscape and weather features to make decisions during various aspects of flight. We examined how Tree Swallows weigh safety against speed in obstacleavoidance trials; how Turkey Vultures use artificial thermals to extend foraging past dusk; the movement ecology of migration in Turkey Vultures, including energetics, route choice, and use of surface features, turbulence, and winds; how migrating vultures vary in their use of these features according to whether they live in mountainous, flat, coastal, or inland environments; and how vultures vary in their use of weather features according to the time of year, and whether they are breeding, over-wintering, or migrating. To examine these questions, we employed a variety of experimental, computational, and statistical techniques. Birds were released in flight tunnels for obstacle avoidance trials, while vultures were implanted with heart rate loggers and tracked via satellite-based GPS to study movements. Weather variables were drawn from the North American Regional Reanalysis, a regional-scale meteorological model. In obstacle avoidance trials, we found no evidence that swallows exhibit side-bias to promote quick decision making. We found that, in nature, Turkey Vultures will forage past their normal daily activity period when presented with both an artificial food source and an artificial thermal, in the form of a methane-vent. A heart rate analysis of a migrating turkey vulture suggests that the act of migration is not energetically costly for soaring migrants. An analysis of movement paths in relation to turbulence, horizontal winds, terrain ruggedness, and other descriptors such as heat flux and boundary layer height shows that movement and navigation correlates with a variety of external factors, most notably turbulent kinetic energy, horizontal winds, and surface ruggedness. We found that the way in which vultures use weather features depends on the time of year, biological motivation, the presence of mountain ranges, and the way in which these variables interact with each other.

Journal / Series

Volume & Issue

Description

Sponsorship

Date Issued

2009-10-13T14:43:30Z

Publisher

Keywords

Flight behavior in Birds

Location

Effective Date

Expiration Date

Sector

Employer

Union

Union Local

NAICS

Number of Workers

Committee Chair

Committee Co-Chair

Committee Member

Degree Discipline

Degree Name

Degree Level

Related Version

Related DOI

Related To

Related Part

Based on Related Item

Has Other Format(s)

Part of Related Item

Related To

Related Publication(s)

Link(s) to Related Publication(s)

References

Link(s) to Reference(s)

Previously Published As

Government Document

ISBN

ISMN

ISSN

Other Identifiers

Rights

Rights URI

Types

dissertation or thesis

Accessibility Feature

Accessibility Hazard

Accessibility Summary

Link(s) to Catalog Record